Analyte sensor with impedance determination

Abstract

Various examples are directed to systems and methods of and using analyte sensors. An example analyte sensor system comprises an analyte sensor and a hardware device in communication with the analyte sensor. The hardware device may be configured to perform operations comprising applying a first bias voltage to the analyte sensor, the first bias voltage less than an operational bias voltage of the analyte sensor, measuring a first current at the analyte sensor when the first bias voltage is applied, and applying a second bias voltage to the analyte sensor. The operations may further comprise measuring a second current at the analyte sensor when the second bias voltage is applied, detecting a plateau bias voltage using the first current and the second current, determining that the plateau bias voltage is less than a plateau bias voltage threshold, and executing a responsive action at the analyte sensor.

What is claimed is: 
     
       1. An analyte sensor system, comprising:
 an analyte sensor comprising a working electrode and a reference electrode, the reference electrode comprising a material that is depleted during use of the analyte sensor; and 
 a hardware device in communication with the analyte sensor, wherein the hardware device is configured to perform operations comprising: 
 applying a first bias voltage to the working electrode of the analyte sensor, the first bias voltage less than an operational bias voltage of the working electrode of the analyte sensor; 
 measuring a first current at the analyte sensor when the first bias voltage is applied; 
 applying a second bias voltage to the working electrode of the analyte sensor; 
 measuring a second current at the analyte sensor when the second bias voltage is applied; 
 detecting a plateau bias voltage using the first current and the second current, wherein the plateau bias voltage is the bias voltage at which a current response stops; 
 determining if the plateau bias voltage is greater than a plateau bias voltage threshold; and 
 executing, in response to determining that the plateau bias voltage is greater than the plateau bias voltage threshold, a responsive action at the analyte sensor. 
 
     
     
       2. The analyte sensor system of  claim 1 , wherein applying the first bias voltage and applying the second bias voltage comprises continuously sweeping the first bias voltage and the second bias voltage of the analyte sensor along a range including the first bias voltage and the second bias voltage. 
     
     
       3. The analyte sensor system of  claim 1 , wherein detecting the plateau bias voltage comprises determining that the first current is less than a current threshold. 
     
     
       4. The analyte sensor system of  claim 1 , the operations further comprising:
 determining a current response of the analyte sensor using the first current and the second current, wherein detecting the plateau bias voltage comprises determining a bias voltage at which a slope of the current response is about zero. 
 
     
     
       5. The analyte sensor system of  claim 1 , the operations further comprising:
 determining stage of life data for the analyte sensor using the plateau bias voltage; and 
 displaying the stage of life data at a user interface. 
 
     
     
       6. The analyte sensor system of  claim 1 , wherein the responsive action comprises applying a compensation to a third sensor current generated by the analyte sensor. 
     
     
       7. The analyte sensor system of  claim 1 , wherein the responsive action comprises:
 ceasing to provide a bias current to the analyte sensor; and 
 displaying at a user interface an indication that a sensor session for the analyte sensor is ended. 
 
     
     
       8. The analyte sensor system of  claim 1 , wherein the analyte sensor is a glucose sensor. 
     
     
       9. The analyte sensor system of  claim 1 , wherein the analyte sensor is a transcutaneous sensor. 
     
     
       10. A method of operating an analyte sensor, comprising:
 applying a first bias voltage to a working electrode of the analyte sensor, the first bias voltage less than an operational bias voltage of the working electrode of the analyte sensor; 
 measuring a first current at the analyte sensor when the first bias voltage is applied; 
 applying a second bias voltage to the working electrode of the analyte sensor; 
 measuring a second current at the analyte sensor when the second bias voltage is applied; 
 detecting a plateau bias voltage using the first current and the second current; 
 determining if the plateau bias voltage is greater than a plateau bias voltage threshold; and 
 executing, in response to determining that the plateau bias voltage is greater than the plateau bias voltage threshold, a responsive action at the analyte sensor. 
 
     
     
       11. The method of  claim 10 , wherein applying the first bias voltage and applying the second bias voltage comprises continuously sweeping the first bias voltage and the second bias voltage of the analyte sensor along a range including the first bias voltage and the second bias voltage. 
     
     
       12. The method of  claim 10 , wherein detecting the plateau bias voltage comprises determining that the first current is less than a current threshold. 
     
     
       13. The method of  claim 10 , further comprising:
 determining a current response of the analyte sensor using the first current and the second current, wherein detecting the plateau bias voltage comprises determining a bias voltage at which a slope of the current response is about zero. 
 
     
     
       14. The method of  claim 10 , further comprising:
 determining stage of life data for the analyte sensor using the plateau bias voltage; and 
 displaying the stage of life data at a user interface. 
 
     
     
       15. The method of  claim 10 , wherein the responsive action comprises applying a compensation to a third sensor current generated by the analyte sensor. 
     
     
       16. The method of  claim 10 , wherein the responsive action comprises:
 ceasing to provide a bias current to the analyte sensor; and 
 displaying at a user interface an indication that a sensor session for the analyte sensor is ended. 
 
     
     
       17. The method of  claim 10 , wherein the analyte sensor is a glucose sensor. 
     
     
       18. The method of  claim 10 , wherein the analyte sensor is a transcutaneous sensor.